1. Field of the Invention
This invention relates to height adjustment or levelling mechanisms for equipment and more particularly though not solely to height adjustment or levelling mechanisms for home appliances such as refrigerators.
2. Description of the Prior Art
Modern levelling foot devices for home appliances, in addition to providing height adjustment of the appliance, increasingly include the addition of wheels or castors to allow the appliance to be moved. However, in order for the levelling foot device to be of benefit to the average household member, the mechanism must be readily accessible and easily adjusted. Early height adjustment mechanisms for home appliances simply consisted of a captive nut in the base of the front of the appliance into which a bolt could be wound (usually requiring a hand tool) to adjust the height (with the bolt head acting as a foot on the ground and rotation of the bolt head adjusting the distance between the head and the captive nut). This system usually requires one person to lift and hold the front of the appliance while a second person adjusts the height of the feet.
Improvements to the above system are disclosed in United States patent numbers U.S. Pat. No. 3,844,578 (Westinghouse Electric Corporation), U.S. Pat. No. 3,856,248 (Labelle), U.S. Pat. No. 3,858,270 (General Electric Company), U.S. Pat. No. 4,783,879 (White Consolidated Industries) and U.S. Pat. No. 5,215,367 (Amana Refrigeration Inc.). Each of the above mechanisms suffer from unnecessary complexity and/or difficulty of use (usually requiring hand tools for adjustment).
An example of a combination height adjustment and roller support mechanism for a refrigerator is disclosed in our New Zealand patent No.239676 published on Feb. 24, 1995 (equivalent to Australian patent No.644541 issued Apr. 22, 1994). The device described therein includes a rotatable hand wheel at the base of the front of the appliance which a user rotates by hand to adjust the height of the front of the appliance (assisted by a fulcrum arrangement). However, it has been found that the user sometimes has difficulty in rotating the hand wheel due to the frictional coupling between the shaft of the hand wheel and its housing within the refrigerator cabinet.
It is, therefore, an object of the present invention to provide height adjustment apparatus for equipment which will go at least some way towards overcoming the above disadvantages or which will at least provide the public with a useful choice.
Accordingly, the invention consists in height adjustment apparatus for varying the height of at least a part of an item of equipment above a support surface, comprising:
fixed locating means which in use is mounted in a base of said item of equipment,
threaded shaft means, adapted to be received by said locating means so that relative rotation there between produces axial movement of said shaft means in relation to said base,
rotatable adjusting means having an end of said threaded shaft means fixed therein and a first bearing surface,
support surface contacting means adapted to contact said support surface and having a second bearing surface, said second bearing surface adapted to contact said first bearing surface to allow relative rotational movement between said rotatable adjusting means and said support surface contacting means, rotation of said rotatable adjusting means thereby adjusting the height of said at least part of an item of equipment.
The invention consists in the foregoing and also envisages constructions of which the following gives examples.